Beater and stock chest combination



Dec. 6, 1955 F. HAYES ,7 ,7

BEATER AND STOCK CHEST COMBINATION Filed Aug. 20, 1952 IN V EN TOR. F RAN K HAYES ATTORNEYS CH EST United States Patent 2,725,794 BEATER AND STOCK CHEST COMBINATION Application August 20, 1952, Serial No. 305,457 4 Claims. (Cl. 92-22) This invention relates to paper stock treatment apparatus and more particularly to a combination of a beater and stock chest together with apparatus for maintaining the stock in the chest in progressive, undisturbed layers proceeding through the chest and back to the beater in the same order in which said stock entered the stock chest.

In the conventional beating apparatus which has been employed in substantially the same manner for many hundreds of years, paper stock is passed through a treatment area formed by the cutter bars of a beater roll and bedplate where the stock receives a refining treatment which effects a cutting, brushing and defibrilation action on the fibers. In conventional beaters it has been necessary hitherto to carry excess stock through the treatment area in order to fill each cell formed by the cutter bars of the beater roll sufficiently to prevent the cutter bars from imparting destructive treatment to the stock. Also it has been considered necessary in the past when using conventional beaters to carry suflicient stock through the treatment area to eifect an adequate recirculation of the stock stream in a batch type tub. Furthermore, in certain installations with conventional beaters it has been standard practice to recirculate the stock from the treatment area back to a stock chest or tub wherein the stock which has already received refining action is mixed with stock which has received no treatment at all. Thus with the conventional apparatus certain of the fibers of the paper stock perhaps never receive any refining action at all because, due to the circulation and mixing in the tub associated with the beater, they may happen to remain in the tub I during the whole beating phase or, they may pass through the treatment area without receiving any treatment. On the other hand, other fibers may return to the stock treatment area many times and thus become excessively refined. The result is that with conventional beaters attainment of a proper average degree of refining is often accompanied by less freeness than is desirable in a portion of the fibers and as a consequence the speed of the paper making operation is materially cut down.

It is an object of this invention to provide stock treatment apparatus in which substantially all of the stock receives treatment for each pass through the stock treatment area and in which substantially all of the stock passes through the treatment area the same number of times, whereby a maximum amount of cutting, brushing, and defibrilation may be accomplished with a minimum loss of freeness.

Another object of my invention is to provide stock treatment apparatus in which the amount of treatment of any part of the stock may be readily determined and in which stock treatment conditions may be varied in accordance with the type of treatment which may be desirable for the stock at any particular moment.

In the accomplishment of these and other objects of my invention, I employ in a preferred embodiment thereof a beater which is provided with very closely spaced cutter bars so that substantially all of the stock carried by the beater roll receives some treatment during each pass separately prior to mixing them.

through the treatment area. beater roll, I employ a bedplate which is adapted to move relative to the beater roll and which is provided with means for regulating the cutting pressure in the treatment area. In conjunction with this beating mechanism, I employ a stock chest in conjunction with apparatus which is particularly adapted to receive the beaten stock and to maintain it in substantially undisturbed layers or strata progressively through the stock chest. At the bottom of the stock chest, I withdraw the stock without disturbing the generally stratified condition of the stock and return the same to the treatment area by means of conventional pumps and conduits. v

It is a feature of my invention that raw stock may be given a properly light treatment for one or two passes through the treatment area, and thereafter the pressure between the bedplate and the beater roll may be substantially increased and the roll velocity may be changed to bring about final fiber development necessary under optimum conditions for the production of high quality paper.

It is a further feature of my invention that the stratified flow brings about a superior and more uniform treatment In conjunction with this a of the stock since already refined stock is not mixed with untreated raw stock.

An additional feature of my invention is that with this type of stratified flow, the time required for necessary fiber development is less and the fiber development is achieved without excessively refining any substantial portion of the stock. The result of this is to provide a maximum stock treatment while maintaining a maximum'freeness, or as is otherwise stated inthe industry, a minimum slowness.

Furthermore, my apparatus provides an exceptionally convenient mechanism for beating various types of stock may be beaten with my apparatus ous treatment of the rag stock Thereafter sulphite pulp may be and the entire batch may be beaten, under conditions which will not be destructive to the more tender fibers contained in the sulphite pulp.

until the required rigorhas been accomplished.

Further objects and features of my invention will best' be understood and appreciated from the following detailed description of a preferred embodiment of my invention, selected for the purpose of illustration, and shown in the accompanying drawings, in which:

The single figure represents partially sectioned view in side elevation of the apparatus of my invention.

The preferred embodiment of my invention herein shown includes in its general organization a base frame 10 upon which a beater roll 12 is mounted for rotation in conventional bearings and being driven in rotation by conventional motor elements, not shown. Associated with the beater roll 12 and likewise mounted within the frame 10 is a bedplate 14 adapted for vertical motion and being actuated vertically by hydraulic elements indicated at 16. The cross-thrust imparted to the bedplate'by the roll 12 is taken up by pivotally mounted holding arms 18 mounted within the base frame 10. Paper stock is pumped to the treatment area between the roll 12 and bed plate 14 through conduits 20 by means of a stock pumping unit indicated at 22. After exit from the beater, paper stock is transferred to a stock chest 24 and is distributed uniformly, in layers therein by means of a stock distribut For instance, rag stock mixed with the rag stock that the stock is pumped into the.

No. 2;610;552,'dated'September '16, 1952. The purpose for this narrow spacing herein employed is primarily to provide a substantial treatment of all stock which passes through the treatment area between the roll 12 and the bedplate 14 so that virtually all fibers which pass through the apparatus will receive some treatment such as cutting, brushing or defibrilation. On the other hand, it should be pointed out that certain of the advantages of Stratified flow herein disclosed may be obtained with a beater having somewhat greater cell spacing and greater bedplate area.

After issuing from the treatment area, the paper stock moves directly to a horizontal conduit 34 having a screw conveyor 36 mounted for rotation therein on a shaft 37 and being driven by a source of power indicated at'38 including a motor, a reduction gear and a chain driving arrangement. At the far end of the conduit 34, stock descends through a vertical conduit 40 to a second horizontal conduit 42 which'is provided with a second screw conveyor 44. The second horizontal conduit 42 is adapted to makea circular sweep around the upper surface of the stock chest24 and is driven through a gear arrangement by the motor 38. The conduit 44 is supported centrally by an annular casting 46 which rests on an outwardly extending flange 48 of the vertical conduit 40. The upper portion of the annular casting 46 is provided with a beveledgear 50 which is engaged by a complementary'beveled gear 52 mounted on the shaft 37. Thus when the shaft 37 is driven in rotation, the gear 52 drives the gear 50 which in turn drives the horizontal conduit 42 in its circular sweeping'motion around the upper surface of the stock chest 24. The second screw conveyor 44 is supported by a shaft 54 within the second horizontal conduit 42 and is driven in rotation by a sprocket 56 mounted at the outer end thereof and meshing in an annular sprocket'track 58 mounted in the upper opening of the stock chest 24. It will be seen also that the annular track 58 serves the further purpose of supporting the outer end of the conduit 42. A longitudinally extending weir 60 .is mounted within the conduit 42, and, by gradually descending along the length of the conduit 42, effects an even distribution of'the stock into the chest 24.

Thus itwill be seen that the stock passes on its way from the heater to the stock chest 24, through the conduit 34 downwardly throughthe vertical conduit 40 and then outwardly through the horizontal conduit 42. As it passes outwardly through the conduit42, the stock spills progressively over the weir 60 and falls into the stock chest 24 evenly and uniformly distributed about the surface thereof. In order to prevent channeling and to preserve the stra'tified and progressive relationship of the stock, I provide the stock chest 24 with a conically formed bottom area 62.

The operation of the apparatus herein described is as follows. Raw or slush pulp is pumped to the beater through a conduit 66 and passes through the treatment area before entering the stock chest 24. At this stage of the operation, it is not necessary to employ the stock distributing mechanism 26 and the stock may be admitted directly to the chest 24 by means of a bypass 64. In a representative example, the stock will be pumped to the beater at a rate of 800 gallons per minute and the stock chest will have a capacity of 3200 gallons. When the stock chest 24 has been filled, conduit 66 is closed off and the pumping unit 22 is put in operation whereby to draw stock 'from' the bottom of the chest 24 and pump it through conduit 20 up to the treatment area of the beater. 'It will "be understood, of course, at this stage all of the stock in the chest 24 will have beenrefined substantially to ,thesame degree. While it has been stated herein that the'beateremploying small cells subjects substantially all fibers passing through the treatment area to some refining action, it should not be considered that each individual fiberisrefinedto exactly thesame degree. Even with the smdll ell spaeingbeater, some'fibers'will *bec'ut, brushed and defibrilated to a 'greater 'degree than others. Once the pumping unit 22 is engaged and the feed of the stock stream to the treatment area is drawn from the bottom of the stock chest 24, then the bypass 64 is closed off and the stock distributing mechanism 22 is put into operation. At this time the horizontal conduit 44 makes a sweeping motion around the upper surface of the stock chest -24, and as stock which has now passed through the treatment area v.for a second time enters the stock chest 24,.it-is distributed evenly inilayers on the surface of the stock already present therein. At the end of four minutesin this illustrationafter the pumping unit has been engaged, all of the stock will have been put through the treatment area for a seconditime anddepositedin successive layers in the chest. It will be seen that in this short time no substantial settling of heavier portions of the stock will take place in the stock chest. The recirculation, of course, may be repeated as many times as is necessary to efiect the desired treatment of the stock, and it will be understood that with this apparatusstock will not be mixed with untreated stock.

When the full fiber development has been attained, the stock may be drawn off'from the bottom of the chest and pumped to the paper making apparatus while new stock is being enteredthrough conduit 66. When this is done, of course, the stock distributing mechanism 26 will continue in operation so that the newly entered stock will not become mixed with the fully treated stock. Also it will be understood that careful coordination mustbe made to cease withdrawing stock from the chest 24 in order to prevent substantially untreated stock from being sent to the paper making apparatus.

While the stock is herein shown as issuing directly from the beater into the chest, it will be understood that the stock may be pumped from the beater to a more remote chest if such is desirable.

Certain other minor variations of this preferred embodiment of my invention will now become apparent to those skilled in the art, and therefore, it is not intended to confine the invention to the precise form herein shown, but rather to limit it in terms of the appended claims.

Having thus described and disclosed an illustrative embodiment of my invention, whatI claim as new and desire to secure by Letters Patent is:

1. Paper stock treatment apparatus including a beater and a stock chest having in combination means in said beaterfor subjecting substantially all fibers of a stock stream to beater type treatment such as cutting, brushing and defibrilation during each pass through said beater, and means for distributing said stock stream in said stock chest so as 'to cause it to flow through said chest in substantially undisturbed layers, and means for returning said stock stream'to said heater in the same order in which said stream entered said chest.

2. 'Paper stock treatment apparatus comprising a beater, a stock chest, means .in said heater for subjecting substantially all 'fibers of a stock stream to beater type treatment such as cutting, brushing and defibrilation during each pass through said beater, means for transferring stockfrom saidbeater to said chest, means for maintaining said stock in said chest in progressive layers correponding to the order of entrance of said stock into said chest, means for withdrawing stock from said chest in substantially the same progressive order in which said stock enteredsaid chest, and mechanism including a pump and conduitfortrans'ferringsaid stock to said beater after said stock'has been withdrawn from said chest.

3. Paper stock treatment apparatus comprising means for beating paper stock including a heater roll and a bedplate, said bedplate being mounted movably with relation to said roll, hydraulic means actuating said bedplate under pressure against said roll, said beater roll adapted to subject substantially all stock passing between it and said bedplate to beater .type refining action, a stock chest having an entrance end and an exit end for paper stock,

means for transferring stock from said beater to the entrance end of said chest, means for distributing said stock in progressive substantially undisturbed layers in said chest, means for withdrawing stock from the exit end of said chest in substantially the same progressive order that said stock enters said chest, and mechanism including a pump and a conduit for returning said stock to said beater.

4. Paper stock treatment apparatus comprising means for beating paper stock including a beater roll and a bedplate, said beater roll being adapted with means including closely spaced cutter bars for subjecting substantially all fibers of a stock stream to beater type refining action for each pass through said beater, said bedplate being mounted movably with relation to said roll, hydraulic means actuating said bedplate under pressure against said roll, a stock chest having an entrance end and an exit end for paper stock, means for transferring stock from said beater to the entrance end of saidchest, means for distributing said stock in progressive substantially undisturbed layers in said chest, means for withdrawing stock from the exit end of said chest in substantially the same progressive order that said stock enters said chest, and mechanism including a pump and a conduit for returning said stock to said beater.

References Cited in the file of this patent UNITED STATES PATENTS 

